Molecular Encapsulation of Frankincense Oil (Boswellia serrata) in β-Cyclodextrin as a Preliminary of the Stability Study

Abstract

Molecular encapsulation is the focus of current research because it is proven to be able to maintain and even to improve the physicochemical properties of their guest molecules. A trapping agent plays an essential role in the success of encapsulation. β-cyclodextrin (β-CD) could be one of the good trapping agents because it has a hydrophobic cavity and a hydrophilic outer surface. β-CD can interact with hydrophobic bioactive compounds as the guest molecules by trapping these compounds into the cavity of β-CD. Frankincense oil (FO) is one of the essential oils. It has been researched and utilized in various fields, but the physicochemical properties of FO make it less stable. This study explains the encapsulation of FO in β-CD. By using the coprecipitation method, this study gives pure crystal, and the efficiency of encapsulation is 78%. The diffraction pattern shown in the ICs identified the pattern of diffraction in crystals with a sharp peak of diffraction, and most of these peaks showed patterns of diffraction in β-CD. The absorption intensity of the pure CD was only 2.5, but after inserting the FO in its cavity, the intensity changed to 2.7 - 2.9. It shows that there is an interaction between the non-covalent part of β-CD and bioactive molecules, which are also known as hosts - guests inclusion complexes (ICs). The results confirmed as well that the ICs formed is more stable as the increase in the boiling point of the ICs in the range of 280-295oC.